(1) Field of the Invention
The present invention relates to a method for optimizing the utilization of hard-shelled crustaceans, e.g., lobsters and crabs, through inclusion of under-utilized by-product components. These methods are also applicable to the processing of easy-to-process clawed lobsters of the Homaridae family, and to easy-to-process crab, e.g., Snow crab, Maryland Blue crab, Alaska King crab, Dungeness crab, Irish crab (Cancer pagurus) and Jonah crab (Cancer borealis) and including species of the genera Panulirus, Jasus and Chelonectes and to lobster-like crustaceans, including some types of prawn, Nephrops norwegicus and freshwater crayfish species. These methods are particularly applicable to the processing of hard-to-process clawless Spiny lobster and Rock lobster species of temperate and tropical origin, as well as to the processing of hard-to-process Northern Stone Crab (Lithodes maja), Porcupine Crab (Neolithodes grimaldii), and Green Crab.
(2) Description of the Prior Art
A traditional method for processing and packaging easy-to-process clawed lobsters of the Homaridae family consisted of cooking them whole, either by steam exposure or by hot water immersion, cooling the product and sealing them in plastic bags containing brine solution with subsequent freezing to render the lobster embedded in ice. Inherent to this traditional lobster frozen-in-brine product, a substantial degree of visceral staining of the edible meat components within the upper tail region was encountered. This was attributed, in part, to migration and rupture of the visceral hepatopancreatic fraction and intestinal tract contents during the preparative cooking procedure. Also inherent to this product were residual heavy-metal contaminants, which were predominately-located in the visceral fraction and which underwent migration to the edible body meat fraction as a result of cooking procedures.
Other traditional methods of processing intact lobsters consisted of freezing cooked lobsters, which were wrapped individually in wax paper in a master-box. Another common method involved the removal of the intact tail section of lobsters with subsequent individual quick-freezing, and packaging the tails through alignment into a box. In such products, the raw lobster material either in an intact form, or as tail sections was prone to problems of breakage due to the brittle nature of their shell material. Particularly, such problems were encountered during distribution and transportation procedures.
The extraction of meat from the body of hard-shelled crustaceans in which the meat is very strongly attached to the shell, e.g., all species of crab, crayfish, lobster, and rock shrimp, as opposed to soft-shelled crustaceans, e.g., all shrimp species, other than rock shrimp, has proved to be very difficult, time consuming and expensive. In present day practices, for obtaining the edible portions from such crustaceans, e.g., all species of lobster, crab, crayfish, rock shrimp, and the like, involved a variety of mechanical, electrical and heat-treatments which included subjecting the crustaceans to a sawing action on the shells, a high or low electrical voltage through the shells, treatment with direct flame, immersion in boiling water or various chemical treatments, or treatment with steam at atmospheric pressure or under high pressures in closed vessels. A myriad of other procedures were also known which involved combinations of some or all of the foregoing methods. While some of the procedures had various degrees of success, most of the prior known procedures required hand labour to treat the individual fresh crustaceans in order to remove the edible flesh.
Both raw and cooked hard-shell sections of processed lobsters have heretofore been subjected to many treating methods, for example, freezing intact for subsequent transformation by boiling for rendering extraction of flavour, or proteinaceous solubles and non-soluble components for further culinary applications. In addition, the head-shell material of either raw or cooked lobster was subjected to grinding reduction and mechanical meat removal procedures.
It was virtually impossible to remove raw lobster meat from head shell without grinding the head shell. Consequently, various mechanical methods have been developed to remove either raw or cooked meat from mechanically-reduced head-shell material. In some techniques, physical separation of the meat from the shell was effected through the use of riffle tank particle separation methods. The broken-up shell effectively settled to the bottom, and the extracted meat was concentrated by water fluming and screen collection. A recognized impediment to this procedure was the loss of desirable and delicate flavour components attributed to the extensive washing procedures during separation.
In other traditional procedures, the cooked head-shells of lobster resulting from hand-shucking processing procedures were subjected to mechanical grinding and reduction through use of perforated rotating drum technology. In this method, the edible meat, and visceral components contained within the head-shell component were separated from the shell fraction by the application of variable belt pressure against a perforated stainless steel drum. The size of the apertures in the drum provided for physical separation of the softer meat and visceral components from the hard brittle shell and cartilaginous skeletal material. Such products arising were commonly recognized as "lobster mince" and found use as culinary ingredients within the food industry.
Many of the difficulties in the removal of the crustacean meat stemmed from the physical structure of the hard crustacean shell, the manner in which the meat was adhered to the shell, the need to extract and maintain the meat in a minimum bacteriologically-contaminated manner, as well as the commercial desire to extract the meat in lump form rather than in many small pieces. The research, both by industry and universities, has been extensive and has resulted in various alleged improvements in the meat extraction processes.
Pre-treatment of the crustaceans by chemicals, the use of certain cooking conditions, the use of machines which squeezed the meat out, or which cored and centrifuged the meat out, or in which air or water blasted the meat out, or which froze and exploded the meat out, have been proposed and advanced with varying degrees of success.
Lobster, and limbs and claws thereof, have been efficiently used and formulated into limb-like or stick-like meat products or claw meat products. After removing the carapaces, gonads, branchiae and internals, the trunks were washed with water and ground-up. Then, the meat remaining in the trunks was recovered with a meat separator and was formulated into minced meat. This meat was further washed with water and the fibrous meat was taken therefrom and was formulated into flakes. Thus, various proteineous parts, including meat remaining in the carapace, the glands, branchiae and meat remaining in the trunks were not utilized, but was disposed of as such.
In the current art and industry of producing meat from the various species of crab it is now common practice to prepare the cooked crab body for removal of the meat by processing the body through a machine which removes the claws, flippers, walking legs and carapace, and then brushes and flushes the visceral cavity. Further machine processing of the prepared body could successfully produce marketable regular mat, but could not remove the backfin lump meat which was considered to be the most valuable product of the crab and which, to date, must be removed by hand picking. An improvement to that processing procedure involved preparing the crab for removal of the lump meat after cooking and removing of the carapace. That procedure involved cutting the side mounds of the body along planes which were disposed at equal acute angles to the bottom shell of the crab and converged to meet along the intersection of the bottom shell and the middle bony ridge, and were outside the inner walls of the collar bones. This exposed the two lump meats, after which a hand tool was inserted into each lump cavity on either side of the lump, and was then compressed and withdrawn, bringing the lump meat with it.
There are many patents which are directed to the processing of such shellfish. Non-limiting examples include the following patents.
U.S. Pat. No. 2,155,308, patented Apr. 18, 1939, by Sterling G. Harris and assigned to The Blue Channel Corporation, provided a procedure for canning crabs, which involved a relatively moderate preliminary heat-treatment in an aqueous fluid, to weaken the tissues by which the portions comprising the carapace, gills and loosely adhering body tissues of the body cavity are attached to the crab, and to remove such portions prior to complete cooking.
U.S. Pat. No. 2,501,655, patented Mar. 28, 1950, by W. M. Altenburg, disclosed a method for loosening lobster meat from its shell by searing the surface of the lobster meat adjacent to the shell, without cooking the interior meat, and subsequently cooling and rapidly freezing the whole lobster.
U.S. Pat. No. 2,858,223, patented Oct. 28, 1958, by Sterling G. Harris, and assigned to The Blue Channel Corporation, provided a method for separating meat from crustacean shells by cooking the meat to shrink it from the shell, then impacting the shell to release the meat, screening the material and then subjecting the screened shell and meat to a flotation separation procedure.
U.S. Pat. No. 2,978,334, patented Apr. 4, 1961, by Lapeyre, and assigned to The Peelers Company, described a general procedure for extracting edible portions of crustaceans, e.g., lobsters, crabs, etc., from the skeletal portions thereof. This included the sequence of freezing and then suddenly lowering the pressure on the outside of the crustacean relative to the internal pressure to explode the shell of the crustacean.
U.S. Pat. No. 3,022,175, patented Feb. 20, 1962 by L. A. Wakefield provided a procedure for the preparation of King Crab legs by severing the legs from the crab body, by cutting the joint or by being manually broken away. The shell was then broken and the legs were removed from the broken shell. The shelled crab legs were then frozen.
U.S. Pat. No. 3,159,992, patented Jun. 9, 1964, by L. C. Fredrickson, provided a method for shelling a crab by first bisecting the shell at the bulb portion of the crab claw between the dactyl and pollex of the claw. The shell segment, including the meat of the bulb portion, was then separated from the shell segment which was integral with the dactyl. The shell segment was then separated from the pollex by bending backwardly to break the skin-like hinge.
U.S. Pat. No. 3,156,949, patented Nov. 17, 1964, by J. P. Moncure, provided methods for processing crabs. The claws, legs, and fins were first broken off. Then, the muscles of the thorax were exposed. In a further procedure, the knuckles and portions of the thorax walls were trimmed away. In a still further procedure, the knuckles were cut away to enable removal of the meat from within the thorax. In yet another procedure, the processing included the steps of breaking off the claws, legs and fins, whereby the crab was reduced to the carapace and thorax and knuckles thereof, grasping the thorax at the lateral sides thereof and removing the carapace and internal organs of the crab, and grasping the thorax by its forward and rear sides and trimming and severing the knuckles and portions of the lateral sides of the thorax. In this way the meat from within the thorax may be removed.
U.S. Pat. No. 3,253,299, patented May 31, 1966, by S. G. Harris, assigned to The Blue Channel Corporation, provided a procedure including breaking off the claws or the legs from the crab by repeatedly striking them in a direction which was transverse to the axis of the body.
U.S. Pat. No. 3,471,894, patented Oct. 14, 1965 by E. W. Tasker, assigned to Cape Ann Marine Research Company Inc., provided a procedure for deshelling crustaceans by placing the crustaceans in a fluid atmosphere, e.g., steam, water or alcohol, and then first subjecting the crustaceans to a first high pressure, and then subjecting them to a rapid decompression step to detach the shells from the flesh.
U.S. Pat. No. 3,513,071 patented May 19, 1970, by Gottlieb Bernhard Fehmerling, provided a method for loosening and then removing edible tissue from the shells of crustaceans, e.g., lobsters, crabs, etc. This included the use of a synergistic combination of enzymes that attacked the connective tissue which held the edible flesh to the shell. The crustaceans were then removed from the enzyme solution bath and were sprayed to remove the edible tissue from the shells.
Japanese Patent No. 46-10898, described a method wherein lobsters, which were in a vacuum chamber and were subjected to vacuum chamber conditions, were exposed to protease enzymes in a temperature range of 50.degree. C. to 55.degree. C. By first vacuum eviscerating the crustaceans with subsequent release of vacuum and injection of steam, the raw meat attached to the shell of the lobster was said to be more effectively separated and could be manually-removed.
U.S. Pat. No. 3,705,040, patented Dec. 5, 1972, by Peter W. Bynagte, and assigned to Westgate-California Foods, Inc., provided a procedure for extracting meat from crustaceans by dipping them in a particular pyrophosphate or metaphosphate solution. The crustaceans were then cooked, and the cooked crustaceans after such procedure were said to be more easily peeled.
U.S. Pat. No. 3,773,962, patented Nov. 20, 1973, by Trelease et al, and assigned to A. Swift & Company, disclosed a method which included cleaning of the stomach and hind-gut of lobster by the use of vacuum evisceration to remove the contents of the stomach and visceral cavity prior to cooking and freezing.
U.S. Pat. No. 4,053,964, patented Oct. 18, 1977, by J. E. Rutledge, provided a procedure for preparing hard-shelled crustaceans for extraction of their body meat from their shells. The first step involved freezing crustaceans either by conventional "quick freezing" techniques or by merely placing the crustaceans in a standard freezer compartment. The next step involved thawing the crustaceans. This thawing was accomplished by simply leaving the crustaceans out at room temperature. The next step involved treating the uncooked crustacean meat in the shell by any of the "conventional" meat extraction procedure. Examples of some "conventional" meat extraction processes included the following. In one extraction procedure, the crustacean had its back shell and leg appendages removed, the remaining shell split into two halves, the internals and fat remove by brushing and washing and finally the cleaned halves passed between two rollers which squeezed the meat out from the shell. In another extraction procedure, the crustacean body was cored and the core placed on conventional centrifuge device to spin the meat out of the core. Another procedure to extract the meat was to use air or water to blow the meat from the crustacean shell after the back and leg appendages had been removed. In yet another method, the crustacean meat could be extracted from the shell by hand.
U.S. Pat. No. 4,340,613, patented Jul. 20, 1982, by Michael P. Moore, described a method for cooking shellfish, e.g., crabs, lobsters, shrimp, and other crustaceans having skeletal portions from which the edible portions are removed prior to consumption. The method included at least partially cooking the shellfish with steam. Then moisture was withdrawn from the at least partially cooked shellfish by subjecting the shellfish to a vacuum at a rate which caused no disruption to the structure of the skeletal portions. This cooking was followed by subjecting the shellfish to vacuum which was said to facilitate mechanical removal of the edible portions from the exoskeleton and/or skeleton portions thereof. Shellfish, e.g., crabs, shrimp, and lobster which were steam-cooked prior to removal of the skeletal portions either by hand or by mechanical means invariably were difficult to separate from the skeletal portions due to the tendency of the edible portion thereof to adhere to the skeletal portions. In particular, mechanical removal techniques employing vacuum-induced meat removal forces were often relatively ineffective when processing shellfish which had been cooked by prior art methods due to the adherence of the edible portions of the cooked shellfish to the skeletal portions and the non-contactive nature of such vacuum removal techniques. The patentee suggested that his method caused the edible portions of the shellfish to shrink to a degree which reduced adherence thereof to the skeletal portions, thereby enabling more rapid and facile removal of said edible portions, especially when vacuum removal techniques were employed.
Other patents taught the production of seafood pastes. Non-limiting examples include the following:
U.S. Pat. No. 4,588,601, patented May 13, 1986, by T. Maruyama et al, and assigned to Kibun Company Limited, provided a method of producing a paste-product, from, e.g., various fish to provide pseudo lobster meat. This included dividing a finepaste product, which had already been coagulated by heating, mixing the divided product with a protein mixture and then moulding the resulting mixture. The mixing and/or moulding procedure was carried out under reduced pressure and then the moulded product was heated.
U.S. Pat. No. 4,816,278, patented Mar. 28, 1989, by Sasamoto et al, and assigned to The Japanese Research and Development Association for Extrusion Cooking, Nippon Suisan Kabushiki Kaisha, Taiyo Fishery Co. Ltd., Kabushiki Kaisha Kobe Seikosho, Ajikan Col Ltd., and Kougyo Co. Ltd., provided a method for processing and treating raw crustaceans, e.g., lobsters, mollusks and seaweed mixtures. This material was mixed together and an optional additive, e.g., soyprotein, wheat flour or starch, was added to the mixture by means of a twin-screw extruder.
U.S. Pat. No. 4,820,529, patented Apr. 11, 1989, by Y. Uchida et al, and assigned to Asahi Denka Kogyo Kabushiki Kaisha, provided a procedure for efficiently-utilizing the meat of crustaceans, e.g., lobster, or crab. This involved utilizing the meat remaining in the trunks and carapaces, by boiling and milling the crustaceans under sufficient conditions for inactivating the enzymes contained therein. Then, added proteolytic enzymes and/or microorganisms were allowed to act thereon.
U.S. Pat. No. 5,560,954, issued Oct. 1, 1996, to Gabriel Elbaz, described a method for preparing a culinary base product from the head-shell of lobster and other crustacean species. This involved a combination of oven heating the intact head-shell material, then subjecting it to mechanical-size-reduction with subsequent emulsification and addition of thickening agents for product stabilization. For the final product, this method provided for the use of both the carapace shell and the soft tissue components.
Thus, none of these conventional methods provided a procedure for separating intact crustacean shell from intact whole raw crustacean meat in order to use by-products and inefficiently-utilized components of crustaceans, and to process hard-to-process crustaceans to provide intact raw crustacean meat while also overcoming the limitations of the prior art.